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Posts Tagged ‘Wolf evolution’

We spend a lot of time debating about how wolves became dogs. A huge debate exists in the archaeological and paleontological literature about how one can determine whether the remains of a canid represent a wolf, a dog, or a transitional form between wolves and dogs. This debate is why the oldest dog remains are dated to around 14,000 years ago and come from the Bonn-Oberkassel site. Anything older than that, a big debate exists among experts about what can be used to define a wolf, a dog, or a transitional form.

But this debate does not exist solely in relatively recent transition between wolves and dogs. The entire evolution of Canis lupus is a hotly contested and often contradictory, depending upon which source one reads and whether one is looking a source that relies upon paleontological and morphological analysis or one that looks at the molecular evolution of the species.

It is well-accepted in European paleontology that Canis lupus evolved from Canis mosbachensis. Mark Derr paid particular attention to this evolution in his How the Dog Became the Dog. He posits that the extinction of the large hunting dog, Xenocyon lycaonoides, created an ecological niche that could be filled by the Mosbach wolf evolving into the gray wolf.

Yes, the Mosbach wolf was smaller than the modern gray wolf. Individuals from Northwestern Europe were mostly about the size of a modern Indian wolf or a “red wolf.” Indeed, the similarities between some of these mosbachensis wolves and red wolves are the best evidence for a unique red wolf species, for one can argue that red wolves are just a relict form of the Mosbach wolf that held on in Eastern North America. Of course, the genetic data do not agree with this assertion, but it is an interesting idea nonetheless.

My reading is that the Mosbach wolf gave rise to Canis lupus in Eurasia between 300,000 and 500,000 years ago. The coyote, though often posited as a primitive Canis, is actually derived from a divergent form of Canis lupus that got marooned in the American Southwest some 50,000 years ago and evolved to fit a jackal-like niche on a continent already dominated by dire wolves.

The Mosbach wolf disappeared from the fossil record around 300,000 years ago, but there is always a debate as to the possibility that it held on longer. The red wolf and Indian wolf are certainly possibilities for its continued existence today, but as we’ve looked at more wolf genomes both of those don’t come out so distinctive. Every study that I’ve seen that uses Indian wolf genomes finds that they are divergent Canis lupus, and the red wolf is a cross between wolves that are of that coyote type and relict Southeastern gray wolves from a later invasion of the continent. I do think there is pretty good historical data that some smaller wolves that we would define as coyotes lived in the Eastern states at the time of contact, particularly the small brown wolf of Pennsylvania mentioned by Shoemaker and the small “wolues” of Jamestown mentioned by John Smith. My guess is that no one really took stock of what they were killing when they killed off the wolves of Eastern states. It is very possible that coyote-like wolves were killed off in great numbers along with the big ones, and later on, coyotes from the plains came East, crossing with wolves and even relict original Eastern coyotes to form the modern Eastern coyote. The red wolf and the larger Eastern coyote are thus recreations of the Mosbach wolf that have happened in modern times.

In Europe, one potential late surviving Mosbach wolf was thought to have been found in Apulia, Italy, at the Grotta Romanelli site. Wolf remains have been found in the cave that date to between 40,000 and 69,000 years ago and they were often described as belonging to a late surviving Mosbach wolf. A recent morphological analysis revealed that these remains were of a peculiar form of Canis lupus that lived in that part of Southern Italy, and they were not of any kind of Mosbach wolf.

However, the Mosbach wolf is particularly intriguing. Occasionally, it has been posited as a direct ancestor of the domestic dog, but because we don’t have an overlap between the signs of the earliest dog domestication and the existence of Canis mosbachensis in the fossil record, one should be very careful in making such an assertion.

This same caveat should be placed when one sees Canis variabilis posited as dog ancestor. For one thing, there is no such thing as Canis variabilis. Instead, all the specimens listed as this species that come from the Zhoukoudian site in China have now been reassigned to Canis mosbachensis. This reassignment posits them as Canis mosbachensis variabilis, so whenever one encounters that “Canis variabilis” in a paper, just remember that they are discussing a particular East Asian form of the Mosbach wolf.

From my own speculative meta-analysis, it seems that the Mosbach wolf is ancestral to the entire wolf/dog/coyote species complex, which may include the African golden wolf, and the Eurasian golden jackal. A genome comparison study that included dogs, wolves, and one Israeli Eurasian golden jackal found that the divergence between the golden jackal and the dog and wolf species happened just before the anatomically modern Canis lupus replaced Canis mosbachensis in the fossil record. The Eurasian golden jackal could potentially be derived from a diminutive form of Canis mosbachensis that moved toward a more generalist scavenger form.

We also have some evidence of small Mosbach wolves in Europe that could have potentially gone in the direction of the golden jackal. This specimen was found not far from the Grotta Romanelli wolf that were found to be anatomically modern and not Mosbach wolves. It was found at the Contrada Monticelli site in Apulia. It was unusual in that it was quite a bit smaller than the Mosbach wolves found in other parts of Europe, and the authors found that Mosbach wolves were as morphologically variable as modern wolves are.

In North Africa, we also have a recent discovery of a canid that was much like the Mosbach wolf. The authors thought it was a bit different from the Eurasian form, and they decided to call this species Canis othmanii. This African wolf-like canid was found at a site in Tunisia and dates to the Middle Pleistocene, and it could potentially be the basal gray wolf that hybridized with the Ethiopian wolf to make the African golden wolf. More work needs to be done on this specimen, for it very well could wind up like Canis variabilis, a regionally distinct form of the Mosbach wolf.

The really fuzzy part about Canis mosbachensis isn’t that it is the ancestor of the gray wolf. The educated speculations I make about its relationship to the golden jackal and the golden wolf could be debated, and we need lots more data to figure out if I am right or not.

The really fuzzy part is what came before the Mosbach wolf. Most scholars think that Etruscan wolf (Canis etruscus), which makes an appearance in the fossil record around 2 million years ago, is the ancestor of the Mosbach wolf. For years, there was a debate about whether the Mosbach wolf was a chrono-subspecies of the Etruscan wolf or a chrono-subspecies of the gray wolf. All these suggestions would be technically true, simply because we could regard the Etruscan wolf-Mosbach wolf-gray wolf as a species that lasted and evolved over this time period.

However, a bit of a debate now exists as to whether the Etruscan wolf is the ancestor of the Mosbach wolf. An extensive morphological analysis of Etruscan wolf remains and those of another Canis species called Canis arnensis, which compared both to the modern black-backed jackal, the gray wolf, the golden jackal, and the golden wolf, found that our previous delineation between arnensis as being jackal-like and etruscus as being wolf-like were over-simplifications. Some characters of arnensis are much more like modern gray wolves than etruscus is, and it is possible that arnesis gave rise to the Mosbach wolf. Still, the bulk of scholarship thinks that the Etruscan wolf is the ancestor of the Mosbach wolf.

However, because the Mosbach wolf was not included in the analysis, it might be difficult to make such a conclusion. However, maybe the Etruscan wolf or something like it is the ancestor of the Ethiopian wolf. The ancestral Ethiopian wolf must have had an extensive range in Northern Africa for it to have hybridized with Canis mosbachensis, Canis othmanii, or a basal modern gray wolf to form the African golden wolf.

I have focused most of this post on the origins of gray wolves in the Old World, but the first Canis species to evolve were found in North America. Canis lepophagus first appeared in the fossil record 5 million years ago. It was very similar to a coyote or a Canis arnensis of the Old World. This is the part of the story where the molecular data has largely shaken up what we used to believe about coyotes. Lepophagus is thought to have evolved into the larger Edward’s wolf (Canis edwardii), which is sometimes called Canis priscolatrans. These animals might have been the same species or very closely related to the Etruscan wolf. The modern coyote is thought to have derived from edwardii/priscolatrans/estrucus 1 million years ago, but genome-wide comparisons put the existence of most recent common ancestor of gray wolves and coyotes at less than 51,000 years ago.

The dire wolf derived from Armbruster’s wolf (Canis armbrusteri). Armbruster’s wolf derived from Canis edwardii/priscolatrans/etruscus 1.8 million years ago. The dire wolf then evolved from that species 125,000 years ago, which means the dire wolf’s most recent common ancestor with modern wolves and the coyote may have been as far back as 2 or even 3 million years ago.

This analysis is still being worked out. The molecular data is constantly throwing wrenches into the machinery of paleontology, especially the paleontology of canids. The most successful extant canid lineage are full of parallel evolution and phenotypic plasticity, and in this way, it has become quite a challenge to sort out the evolutionary history of these species. At various times, large wolf-like forms have evolved as have smaller coyote or jackal-like forms.

The story of Canis starts with a coyote-like lepophagus, but right now, its likely niche is adopted by the modern coyote, which also very similar to it. But the molecular data suggest that the coyote evolved to adopt this similar niche from a larger Eurasian gray wolf and that it did not directly descend from lepophagus over 5 million years in only North America. Instead, it evolved into wolves that wandered into Eurasia, becoming the Mosbach wolf and then anatomically modern gray wolf. Some of these wolves wandered back into North America and became generalist scavengers in the land of the dire wolf.

Very similar stories likely are lost to us, but we must understand that the history of wolves is not just about getting bigger and developing pack-hunting behavior. That is one part of the story, but another part is about evolving to fit niches, which sometimes means evolving a smaller size and more generalist diet.

Some of my ideas here are very speculative, but I think they are nested in my reading of the available literature. Do not assume that I have the final story of how these creatures evolved, but just understand that the molecular side is so rarely considered in paleontology literature that it is almost like we’re reading evolutionary history of two different lineages.

More work must be done to formulate a synthesis between these two disciplines. Otherwise, there will be continued conflict, and the one using an older methodology and often working with much more incomplete data-set will fall by the wayside. And that is not the one using full genomes.

If we know what problems exist using morphological studies on extant and recently extinct canids, it is very likely that we’re missing important data on many extinct species, one for which there is no DNA to test.

Still, paleontology has much to tell us about the way early wolves lived. It can tell us much about how the ecosystems were and why wolves evolved in the way they did. But its methodologies often miss relationships between extant forms and miss the tendency toward parallel evolution.

I tried for about two years to watch Joe Rogan’s interview with Dan Flores, who wrote a book on coyotes that I think is quite full of misunderstandings about canid taxonomy. When Rogan questioned him about the papers that show a recent origin for the red wolf, Flores pretty much just dismissed those papers because they didn’t look at fossil.

That’s not how it works. Within canids, we know that parallel evolution is a big thing, and it is very possible that coyote-like and red wolf-like canids have evolved more than once on this continent. Indeed, a careful reading of the paleontology and molecular data strongly suggests that this is the case.

In fact, it has always been the case with these wolf-like canids. Big ones evolved from small ones, but sometimes, the big ones become small, because it is a better fit for survival.

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Source.

This post is a hoax.

Do not quote it as fact.

It is nothing more than an April Fools’ Day hoax.

The only part of it that is true is that my great great grandparents’ homestead is on Lower Run. There is a hunt club nearby, but it is on the Calhoun County side.

I hope there is no Ken Olsen who works for the US Geological Survey, because the one in my post was entirely fictitious. His name comes the late Stanley Olsen, who was an expert on ancient dog remains that were found in archeological digs, and then I played around with Stanley to get Stan and finally Ken.  If it had existed, I am sure Stanley Olsen would have loved to have examined that dire wolf skeleton. But that’s as far as the resemblance goes.

Dire wolves went extinct in the great extinction that happened in North America about 12,000 years ago.  It is unlikely that anyone will find one younger than10,000 years old.

I deleted a comment by Lane Batot yesterday, mainly because I wanted to see how many people would fall for the post.

(Please forgive me. I am juvenile.)

Lane was interested in exactly what a dire wolf was, and if we had a good DNA sample, we could figure out where these animals fit in the genus Canis. Lane was interested in knowing if it might be possible that dire wolf genes could be in modern North American wolves.

Good question!

I’m going to some posts on the evolution of Canis in the next few days.

***

I hope you can forgive me for my antics. I’m from West Virginia, and April 1 is taken very seriously here.

And I am not the only person who has engaged in these sorts of internet hoaxes.

My favorite hoax is the one on Minnesota bull sharks. It is the gold standard in these April Fools’ pranks.

However, it is not the only good one.

Last year, the Carolina parakeet was rediscovered.

Now, these things aren’t that hard to write.

It just takes a bit of pseudo-knowledge and a bit of imagination to write a piece of Grade A bull-plop.

So if you see something fantastic on this blog on April 1 again, it may not be true.

Remember, I am not without a sense of humor. I hope that you don’t get too angry with me over this revelation.

***

This is the supposed range map for the dire wolf. West Virginia wasn’t part of its range:

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A dire wolf skeleton discoverd in Gilmer County, West Virginia, proves that the species lived as recently as 300 years ago. This finding will rewrite the natural history of wolves in North America.

 

A few weeks ago, I received a heads up about a discovery that happened just a few miles from where I grew up. Indeed, this discovery happened not too far from my great great grandparents’ homestead on Lower Run, which is just near the line between Calhoun and Gilmer Counties in West Virginia. This discovery happened last August. It is only now that the full results have been released to the public. The exact location has not been revealed.

It seems that a member of a local hunt club, who shall remain anonymous, was exploring a cave that is known for having lots of Indian arrowheads on the cave floor. Over the years, most of the arrowheads have been taken out. This individual was checking out the far reaches of this cave when he came across some bones.

After shining his flashlight over them, he discovered that they were of some sort of large dog. Indeed, he thought they might belong to a St. Bernard that had run away a few years ago.

However, there was no hair around the skeleton. The only thing left was the bones. He called the DNR to report the find. Then the US Geological Survey got involved.

And that’s when things got interesting.

It turns out that the skull for this skeleton was not at all like that of a St. Bernard. It was obviously that of a wolf.

And a very robust one at that.

It had much larger teeth than any known gray wolf population.

Indeed, its anatomy most closely resembled the dire wolves that were taken out of the La Brea tar pits.

However, there was one problem with these remains being those of a dire wolf.

They were radiocarbon dated to the mid-seventeenth century to the early eighteenth century.

Europeans had not yet penetrated beyond the Blue Ridge when this wolf had died.

However, its remains are far more recent than any dire wolf skeleton yet discovered.

This finding means that dire wolves lived during the modern era.

Ken Olsen, the paleontologist leading the multidisciplinary investigation into the Gilmer County dire wolf, says that these findings are earth shattering:

“Apparently dire wolves were able to survive in North America much longer than we thought. That means that European settlers and explorers could have come in contact with this truly monstrous wolf.”

There are so many descriptions of giant wolves on the North American frontier. Perhaps that is why we have legends like the Shunka Warakin, the Waheela, and the giant Ontario white wolf. Maybe they were actually dire wolves.

Olsen says the reason why no other recent dire wolves have been discovered is that the wolves probably were not that common.

“They were probably reduced to a relict population around the end of the last ice age.  There probably weren’t many of them anywhere.”

The fact that this cave is on an historic major migration for Eastern bison intrigues Olsen:

“We know that dire wolves were big game specialists. We also know that the Eastern bison were the largest of the North American bison, and only a wolf truly specialized to bringing down big game could regularly prey upon them.”

Why the dire wolf went extinct without any mention without any historical mention of them is a good question.

“Perhaps settlers killed dire wolves without realizing that they represented a unique species. It is suggested that coyotes, which were once endemic to the East, were killed without any understanding that they were unique from gray wolves.”

Olsen also speculates that canine disease could have wiped out the wolf population before Europeans settled this part of West Virginia.

“The earliest settlers came to this part of West Virgina in the period between the French and Indian War and the Revolution. It is unlikely that this dire wolf ever saw a European or that a European ever saw it. It is possible that the dire wolves went extinct before Europeans crossed the Blue Ridge. Maybe dire wolves were susceptible to diseases that were carried by European dogs. Something similar happened to the dogs of the Native Americans. They simply had no immunity to the pathogens that European dogs carried.”

The dire wolf skeleton is being searched for possible DNA samples.  The exact position of the dire wolf in genus Canis is not entirely clear.

However, we do know that Canis dirus was still around as recently as 300 years ago.

And that is a truly remarkable find.

These dire wolf remains are going to rewrite the story of Canis on the North American continent.

I wonder if any other remains from recent dire wolves are going to be found. I think that it is likely, but it also likely that dire wolf remains have been misidentified as those of unusually robust gray wolf specimens.

Maybe the museum collections have some other remains that haven’t been identified as dire wolves.

Maybe.

But one thing is clear:

The story of wolves in North America needs to be rewritten.

***

Update: Do not write a comment without reading this.

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Remember the post in which I analyzed the study that said dogs were 31,700 years old?

My biggest criticism of the study is that we have already seen extensive studies of dog molecular evolution that suggests that dogs come from East Asian wolves 15,000 years ago. I wanted to know how this study could square with that data.

Well, it turns out that it could square quite well, if we accept this study of mitochondrial DNA at Mathilda’s Anthropology. Essentially, the Europeans did have dogs at this time, but these animals were replaced with Asian dogs, at least in their matriline.

Why this happened is a good question. Perhaps Asian dogs were more fecund, or they had traits that made them of greater utility to domestic dogs. It is very hard to figure out.

This study adds further evidence we currently have only a fraction of the genetic diversity that once existed in the dog and wolf populations throughout the world.

This study also suggests that we definitely domesticated dog more than once. It’s just that one population of dogs wound up being superior to the others for some reason.

We also need to keep in mind that Asian wolves are also much more genetically diverse than any other populations of wolf. In fact, this diversity is so strong that some subspecies have been proposed to be separate species. I am, of  course, talking about the Indian wolf and Himalayan wolf.

I am not entirely convinced that they are separate species. Instead, I think their divergent genetics should be analyze in light of the studies that rather firmly suggest that wolves were originally a very diverse species.

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